The results will be presented at the American College of Medical Genetics (ACMG) 2009 Annual Meeting in Tampa, FL.

Phase 2 Extension Study Overview:

Twenty-six subjects completed either 12 or 24 weeks of treatment during Phase 2 studies. Twenty-three of the 26 subjects continue to receive treatment in an ongoing extension study designed to evaluate the long term safety and efficacy of Amigal. Ten of the 23 subjects have been on treatment for at least 2 years and 4 subjects have been on treatment for more than 3 years.

Preliminary Results:

Treatment with Amigal was generally well-tolerated, with no drug-related serious adverse events. The most common adverse events were headache, arthralgia and diarrhea.

Subjects identified as responders to Amigal at the completion of the Phase 2 studies continued to maintain elevated levels of the target enzyme (a-Gal A), as measured in white blood cells, and reduced levels of the target substrate (kidney GL-3), as measured in urine.

A reduction of GL-3 levels was also observed in interstitial capillary cells from kidney biopsies. Previously reported Phase 2 results indicated that little to no GL-3 was detected in these cells in most subjects prior to treatment with Amigal. The new data were obtained from the retesting of biopsies using an improved methodology.

Preliminary results from the evaluation of modified doses and a new dosing regimen were also presented.

Derralynn Hughes, MA, DPhil, MRCPath, Senior Lecturer in the Haematology Department Academic Haematology, Royal Free & University College Medical School, London, UK, stated, "The data with migalastat continue to be encouraging. I believe migalastat has the potential to be an important new treatment option for Fabry patients."

John F. Crowley, President and CEO of Amicus Therapeutics, added, "We are very pleased with this additional set of Phase 2 data and are very confident we have a solid basis for a successful Phase 3 program. We continue to work in collaboration with the FDA and remain on track to finalize our protocol and initiate the Phase 3 program in the second quarter of this year."

In January 2009, Amicus announced that the FDA supports a Phase 3 clinical trial comparing Amigal to placebo based on a surrogate primary endpoint of the change in the amount of kidney GL-3, the substrate that accumulates in the cells of Fabry patients. The Company expects to finalize the protocol and initiate Phase 3 development in the second quarter of this year.

Amicus is developing Amigal as part of a strategic collaboration with Shire Human Genetic Therapies (HGT), a business unit of Shire plc, to develop and commercialize Amicus' three lead pharmacological chaperone compounds for lysosomal storage disorders. Under the agreement, Shire received commercial rights outside of the United States. Amicus retains all U.S. rights.

Fabry disease is a lysosomal storage disorder caused by inherited genetic mutations in the GLA gene, which result in deficient activity of the enzyme alpha-galactosidase A (a-Gal A). Deficient a-Gal A activity leads to lysosomal accumulation of globotriaosylceramide (GL-3), which is believed to cause the various symptoms of Fabry disease, including pain, kidney failure and increased risk of heart attack and stroke. Amigal is designed to selectively bind to and stabilize a-Gal A, which facilitates proper trafficking of the enzyme to the lysosomes, where it is needed to break down GL-3.

Fabry disease is estimated to affect approximately 5,000 to 10,000 people in the developed world, but recent evidence suggests that the disease may be significantly under-diagnosed. The U.S. Food and Drug Administration's Office of Orphan Products Development has granted orphan designation for Amigal in the United States, and the European Commission has designated Amigal as an orphan medicinal product in the European Union.

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